This invention relates to a discharge fluid skimmer unit for removal of the fine dust from the discharge fluid of a cyclonic-type particle separator or the like.
Cyclone separators are widely employed in industry for the separation of treated particulate products from a moving or carrier fluid. For example in the drawing of grain, and similar materials, the wet grain is passed through a rotating dehydrating drum by a suitable hot air carrier resulting in the drying of the material. When discharged from the dehydrating drum, the dry material must of course be separated from the air. A cyclonic separator is a well-known apparatus used for separating of such dried products from the air, with recycling or discharge of the air to the atmosphere. In a cyclone separator, the particle laden air is introduced into a top upper circular housing having a bottom conically shaped housing with a bottom discharge opening. The air is introduced tangentially and circulates through the upper housing. An air discharge duct is mounted concentrically of the top housing and terminates within the separator below the inlet opening. The particles tend to concentrate in an outer air layer adjacent the outer wall of the top wall section and drop downwardly into the discharge conical housing of the separator. The carrier air is drawn back upwardly through the central air exhaust tube for recirculation and/or discharge to the atmosphere. For example, in a grain dryer, the exhaust air may be recirculated back to the drying furnace apparatus for appropriate use therein. All of the air cannot be recycled and at least part of the exhaust air must be discharged to the atmosphere or otherwise processed by some other discharge means provided. Although cyclone separators provide satisfactory separation or have been widely employed, the discharged air may carry a substantial quantity of fine particles. Where the total amount or more of the exhaust air is recirculated, a source of undesired pollution may be created. The prior art has suggested that a skimmer assembly employing a further centrifugal action be secured to the top of the cyclone separator to further concentrate the fine particles in the peripheral portion of the skimmer for removal and particularly as the part of recycled air while discharging of exhaust air with a minimum of pollutants.